This invention relates to a process for recovering tungsten, scandium, iron, and manganese values from tungsten bearing material. More particularly, it relates to a process for recovering these values from material resulting from the processing of tungsten ores.
In the processing of tungsten ores such as scheelites, wolframites, hubnerites, etc. or mixtures of the same, typically by digesting in basic medium as sodium hydroxide or sodium carbonate, the calcium, iron, and manganese present in the ores are precipitated or form an insoluble material which is separated from the resulting tungstate solution by filtration. Since the ores vary in composition, this insoluble material can also contain elements such as scandium, arsenic, antimony, niobium, and possibly sulfur and phosphorus. Also, because the digestion of tungsten is usually never complete, the residue contains tungsten.
It would be highly desirable to reclaim the tungsten values and other valuable elements as scandium, iron, and manganese from these residues from both an economic and an environmental standpoint.